Portion of a midsole of a footwear article



The sole FIGURE is a rear, side perspective view of a portion of a midsole of a footwear article showing my new design.

The broken lines shown in the sole FIGURE are included for the purpose of illustrating environmental elements only and form no part of the claimed design. All surfaces not shown form no part of the claimed design. 

I claim the ornamental design for a portion of a midsole of a footwear article, as shown and described. 